Assessment of radioactive materials and heavy metals in the surface soil around uranium mining area of Tongliao, China

• Radionuclides around Tongliao uranium mining area in China were firstly reported.
• Heavy metals of surface soil around Tongliao uranium mining were firstly presented.
• Health risk of radionuclides and heavy metals were assessed for local populations.
• Strong positive correlations between radionuclides and heavy metals were identified.

Natural and artificial radionuclides and heavy metals in the surface soil of the uranium mining area of Tongliao, China, were measured using gamma spectrometry, flame atomic absorption spectrophotometry, graphite furnace atomic absorption spectrophotometry and microwave dissolution atomic fluorescence spectrometry respectively. The estimated average activity concentrations of 238U, 232Th, 226Ra, 40K and 137Cs are 27.53±16.01, 15.89±5.20, 12.64±4.27, 746.84±38.24 and 4.23±4.76 Bq/kg respectively. The estimated average absorbed dose rate in the air and annual effective dose rate are 46.58±5.26 nGy/h and 57.13±6.45 μSv, respectively. The radium equivalent activity, external and internal hazard indices were also calculated and their mean values are within the acceptable limits. The heavy metal concentrations of Pb, Cd, Cu, Zn, Hg and As from the surface soil were measured and their health risks were then determined. Although the content of Cd is much higher than the average background in China, its non-cancer and cancer risk indices are all within the acceptable ranges. These calculated hazard indices to estimate the potential radiological health risk in soil and the dose rate are well below their permissible limit. In addition the correlations between the radioactivity concentrations of the radionuclides and the heavy metals in soil were determined by the Pearson linear coefficient.